// HaikuOS null驱动移植到ZENrs的实现

const std = @import("std");
const driver_manager = @import("driver_manager.zig");
const api = @import("api.zig");

// 导入驱动接口定义
const DeviceInfo = driver_manager.DeviceInfo;
const DriverInterface = driver_manager.DriverInterface;

// 驱动私有数据结构
const HaikuNullDriverData = struct {
    allocator: std.mem.Allocator,
    // 在这个简单驱动中不需要额外的私有数据
};

// IO控制命令
pub const IOCTL_READ = 0x01;
pub const IOCTL_WRITE = 0x02;
pub const IOCTL_GET_INFO = 0x03;

// 设备信息
const DeviceDescription = struct {
    name: [32]u8,
    version: u32,
    description: [128]u8,
};

// 初始化驱动
fn init_driver(allocator: std.mem.Allocator, driver_data: *anyopaque) bool {
    std.log.info("HaikuOS NullDriver (ZENrs): 初始化驱动");
    
    // 分配驱动私有数据
    const driver_priv_data = allocator.create(HaikuNullDriverData) catch {
        std.log.err("HaikuOS NullDriver (ZENrs): 无法分配驱动数据");
        return false;
    };
    
    // 初始化驱动数据
    driver_priv_data.* = HaikuNullDriverData{
        .allocator = allocator,
    };
    
    // 存储驱动私有数据
    @atomicStore(*anyopaque, driver_data, @as(*anyopaque, @ptrCast(driver_priv_data)), .Release);
    
    return true;
}

// 清理驱动
fn deinit_driver(driver_data: *anyopaque) void {
    const driver_priv_data = @as(*HaikuNullDriverData, @ptrCast(@alignCast(driver_data)));
    
    std.log.info("HaikuOS NullDriver (ZENrs): 清理驱动");
    
    // 释放驱动私有数据
    driver_priv_data.allocator.destroy(driver_priv_data);
}

// 探测设备
fn probe_device(device_info: *DeviceInfo) bool {
    std.log.info("HaikuOS NullDriver (ZENrs): 探测设备: {s}", .{device_info.name});
    
    // 在这个简单驱动中，我们接受所有设备
    return true;
}

// 移除设备
fn remove_device(device_id: u64) void {
    std.log.info("HaikuOS NullDriver (ZENrs): 移除设备: {d}", .{device_id});
    
    // 在这个简单驱动中，没有特定的移除操作
}

// IO控制函数
fn ioctl_device(device_id: u64, cmd: u32, data: *anyopaque, size: u64) isize {
    std.log.info("HaikuOS NullDriver (ZENrs): IO控制命令: {d}, 设备ID: {d}", .{cmd, device_id});
    
    // 根据命令类型处理请求
    switch (cmd) {
        IOCTL_READ => {
            // null驱动的读取总是返回0字节，模拟HaikuOS的行为
            return 0;
        },
        IOCTL_WRITE => {
            // null驱动的写入总是返回请求的长度，但实际上不做任何操作
            return @as(isize, @intCast(size));
        },
        IOCTL_GET_INFO => {
            // 返回设备信息
            if (size < @sizeOf(DeviceDescription)) {
                return -1;
            }
            
            const device_info = @as(*DeviceDescription, @ptrCast(@alignCast(data)));
            
            // 复制设备名称
            const name = "haiku_null_driver";
            @memcpy(device_info.name[0..name.len], name);
            device_info.name[name.len] = 0;
            
            // 设置版本号
            device_info.version = 1;
            
            // 复制设备描述
            const desc = "HaikuOS null driver ported to ZENrs";
            @memcpy(device_info.description[0..desc.len], desc);
            device_info.description[desc.len] = 0;
            
            return @sizeOf(DeviceDescription);
        },
        else => {
            std.log.warn("HaikuOS NullDriver (ZENrs): 不支持的IO控制命令: {d}", .{cmd});
            return -1;
        },
    }
}

// 驱动接口定义
pub const haikuos_null_driver_interface = DriverInterface{
    .name = "haikuos_null_driver",
    .description = "HaikuOS null character device driver ported to ZENrs",
    .version = 1,
    .init = init_driver,
    .deinit = deinit_driver,
    .probe = probe_device,
    .remove = remove_device,
    .ioctl = ioctl_device,
};

// 导出驱动接口
// 这是ZENrs驱动管理器用来获取驱动接口的函数
export fn haikuos_null_driver_get_interface() *DriverInterface {
    return &haikuos_null_driver_interface;
}